Artificial intelligence in digital pathology approach identifies the predictive impact of tertiary lymphoid structures with immune-checkpoints therapy in NSCLC.
Authors: Mehrdad Rakaee, Elio Adib, Biagio Ricciuti, Lynette M. Sholl, Weiwei Shi, Joao Victor Machado Alessi, Alessio Cortellini, Claudia A.M. Fulgenzi, David J. James Pinato, Sayed MS Hashemi, Idris Bahce, Ilias Houda, Simin Jamaly, Sigve Andersen, Tom Donnem, Mark M. Awad, David J. Kwiatkowski
Journal: Journal of Clinical Oncology (2022)

9065 Background: The presence of Tertiary Lymphoid Structures (TLS) in multiple cancer types has been recognized as a potential predictive biomarker for response to immune-checkpoint blockade. However, there is no standardized method to quantify their presence. In this context, Artificial Intelligence (AI)-based assessment of histology images may well contribute to improve reproducibility, accuracy and speed of TLS quantification. Methods: We developed an automated workflow for quantification of TLS on digitized H&amp;E slides through A) pixel-level classification of tissue using supervised artificial neural networks model, B) object-level cell classification of candidate TLS regions, C) merging the two approaches for curation and validation of TLS versus non-TLS regions. 433 advanced stage non-small cell lung cancer (NSCLC) patients treated with first or subsequent line of anti-PD-(L)1 single agent at DFCI were included in this study. Results: TLS were detected in 37% (n = 161) of the patients H&amp;E slides, with the highest score of 4.7 TLS per mm2 (interquartile range: Q1 = 0, Q2 = 0, Q3 = 0.03 TLS/mm2). TLS density (per mm2) was significantly higher in surgically resected (n = 246; TLS POS = 49%) compared to bioptic samples (n = 187; TLS POS = 21%). No association was observed between TLS and tumor mutational burden (TMB) or PD-L1 protein expression as continuous variables. Among clinically actionable mutations, EGFR (all subtypes) mutated patients (n = 38) had a significantly lower number of TLS compared to patients without EGFR mutations. Patients with ≥ 0.01 TLS/mm2 had a significantly higher objective response rate (32% vs 22%, p = 0.03), a significantly longer median progression-free survival (PFS, 4.8 vs 2.7 months, HR: 0.73, 95% CI: 0.59-0.90, p = 0.004), and a significantly improved median overall survival (OS, 16.5 vs 12.5 months, HR: 0.72, 95% CI: 0.57-0.92, p = 0.008). In multivariable analysis, after adjusting for PD-L1 (≥ vs &lt; 50%), TMB (≥ vs &lt; 10 mu/Mb), sex, age, ECOG score, smoking and line of treatment, TLS/mm2 (≥ vs &lt; 0.01) levels were found to be an independent positive predictive factor for both PFS (HR:0.69, 95% CI: 0.54-0.88, p = 0.003) and OS (HR: 0.70, 95% CI: 0.52-0.93, p = 0.01). Conclusions: These findings suggest that TLS status is an independent predictor of immunotherapy effectiveness in NSCLC, with predictive value similar to that of PD-L1 expression and TMB. This novel AI system has potential for automated identification and quantification of the TLS on digital histopathological slides, and could be utilized in a standard pathology workflow with relative ease. These findings are currently being validated in other solid tumors and cohorts.